In recent years, the use of light-emitting diodes (LEDs) in development of light fixtures for various common lighting purposes has increased, and this trend has accelerated as advances have been made in the field. Indeed, lighting applications which previously had typically been served by fixtures using what are known as high-intensity discharge (HID) lamps are now being served by LED light fixtures. Such lighting applications include, among a good many others, roadway lighting, factory lighting, parking lot lighting, and commercial building lighting.
In many of such products, achieving high levels of illumination over large areas with specific light-distribution requirements is particularly important. One example is fixtures for roadway lighting, an application in which the fixtures are generally placed along roadway edges while light distribution is desired along a significant portion of roadway length and, of course, on the roadway itself—generally to the exclusion of significant light off the roadway. And in such situations it is desirable to minimize the use of large complex reflectors and/or varying orientations of multiple light sources to achieve desired illumination patterns.
Achieving appropriate light distribution while avoiding or minimizing the use of complex reflectors and/or varying orientations of multiple light sources requires the use of lens systems for that purpose. And, where lens alignment plays a role in lens systems, maximizing their effectiveness requires high precision in lens alignment.
At the same time, it must be recognized that what is involved in manufacture of LED light fixtures for roadway illumination and the like is mass, preferably highly efficient, manufacture of light fixtures, rather than manufacture of extremely high-cost precision instruments such as for laboratory usage or the like. More specifically, it is of great importance that the economics of low-cost, high-efficiency manufacture be satisfied, but while still achieving the high-precision lens alignment necessary to maximize performance of high-luminance LED light fixtures for roadway illumination and the like.